WO1994017566A1 - Radar apparatus - Google Patents
Radar apparatus Download PDFInfo
- Publication number
- WO1994017566A1 WO1994017566A1 PCT/EP1994/000093 EP9400093W WO9417566A1 WO 1994017566 A1 WO1994017566 A1 WO 1994017566A1 EP 9400093 W EP9400093 W EP 9400093W WO 9417566 A1 WO9417566 A1 WO 9417566A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- radar
- cassegrain antenna
- radar apparatus
- gun
- dataprocessor
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
- H01Q19/10—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces
- H01Q19/18—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces
- H01Q19/19—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces comprising one main concave reflecting surface associated with an auxiliary reflecting surface
- H01Q19/195—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces comprising one main concave reflecting surface associated with an auxiliary reflecting surface wherein a reflecting surface acts also as a polarisation filter or a polarising device
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F41—WEAPONS
- F41G—WEAPON SIGHTS; AIMING
- F41G3/00—Aiming or laying means
- F41G3/06—Aiming or laying means with rangefinder
Definitions
- the invention relates to a radar apparatus for the auto ⁇ matic tracking of targets and the steering of a gun equipped with servo motors, comprising a Cassegrain antenna provided with a parabolic reflector and a flat mirror, the parabolic reflector being provided with polarization- dependent reflection means and the flat mirror with polarization-twisting reflection means, a feedhorn which is centrally positioned in an aperture of the flat mirror for transmitting and receiving radar radiation via the Cassegrain antenna, a radar transmission device and radar reception device, both connected to the Cassegrain antenna and a radar dataprocessor and servo control device.
- a radar apparatus of this kind is known from, for instance, M.I. Skolnik's "Introduction to Radar Systems", second edition, pp. 242-243.
- a search or a track movement is obtained by steering the flat mirror with for instance servo motors.
- This allows only a limited angle of aperture for the known radar apparatus.
- servo motors that are capable of rotating the complete Cassegrain antenna, must be added. This increases cost and actually renders the control of the flat mirror superfluous.
- the radar apparatus eliminates this disadvantage and is characterized in that the Cassegrain antenna is mounted to a substantially non- recoiling part of the gun barrel and in that the radar reception device, radar dataprocessor and servo control device are designed for the control of the servo motors such that the gun and the Cassegrain antenna mounted on it are capable of automatically tracking a target in a first operational mode.
- the possibility of controlling the flat mirror may now be advantageously used for the instantaneous generation of a lead angle, using simple control means.
- a favourable embodiment of a radar apparatus according to the invention is therefore characterized in that the flat mirror is provided with actuators controlled by the dataprocessor for generating, in a second operational mode, an angular offset between the gun centre line and a line of sight of the Cassegrain antenna.
- a possible disadvantage of mounting the Cassegrain antenna to the gun is that, when firing a salvo, vibrations from the gun may be propagated to the antenna. This may cause a rotational vibration around the centre of gravity of the Cassegrain antenna and consequently adversely affect the accuracy of the target position measurement.
- the measurement of the error angles of a target using a monopulse or a conical scan radar reception device is known to be susceptible to this.
- An additional favourable embodiment of the radar apparatus according to the invention is therefore characterized in that the Cassegrain antenna is provided with rotation sensors for the detection of rotational vibrations induced by gun fire and in that the dataprocessor is capable of generating control signals on the basis of the rotation sensors output signals for controlling the actuators such that the line of sight of the Cassegrain antenna is at least substantially independent of the rotational vibrations.
- vibrations may also bring about a translation in the direction of the line of sight.
- This translation will cause stationary objects to have an apparent Doppler velocity an may cause an apparent change in the Doppler velocity of a target.
- Both effects may degrade the performance of the radar apparatus that is always of the Doppler radar type i the application as described here. This especially holds true if the radar apparatus operates at relatively short wavelengths. This is also true for the radar apparatus described here. Only for short wavelengths the parabolic reflector will be so small that mounting to a gun becomes attractive.
- An other favourable embodiment is therefore characterized in that the Cassegrain antenna is provided with translation sensors for the detection of gunfire-induced, translational vibrations in a direction of the line of sight and in that the dataprocessor is capable of generating control signals on the basis of translation sensor output signals for controlling the actuators such that for the transmitted and received radar radiation, the translation is at least substantially compensated.
- Fig. 1 indicates how a Cassegrain antenna and a gun can be built as one assembly
- Fig. 2 represents a possible version of a Cassegrain antenna according to the invention
- Fig. 3 represents a diagram of a first embodiment of the radar apparatus in operation with the gun
- Fig. 4 represents a diagram of a second embodiment of the radar apparatus in operation with the gun, in which provisions have been made to compensate for the vibrations induced by the gun.
- Fig. 1 shows how Cassegrain antenna 1 and a gun 2 can be built as one assembly.
- the gun is provided with a barrel 3 that recoils heavily upon firing a round and with a barrel guide 4 that recoils only lightly upon firing a round.
- the gun is provided with a servo motor 5 for the azimuth rotation of barrel 3 and a servo motor 6 for the elevation rotation of barrel 3.
- Cassegrain antenna 1 is mounted to barrel guide 4.
- the positioning near barrel 3 yields only a small parallax error between the centre line of barrel 3 and the sight line of Cassegrain antenna 1 and ensures that Cassegrain antenna 1 reliably follows each movement made by barrel 3.
- Fig. 2 shows the Cassegrain antenna 1 in sectional view.
- a feedhorn 7 of the monopulse type or of the conical scan type transmits radar radiation with a predetermined polarization direction to the parabolic reflector 8.
- Parabolic reflector 8 is provided with polarization- dependent reflection means, for instance metal wires that are positioned such as to reflect the polarized radar radiation. If, for instance, the radar radiation is horizontallay polarized, a near-complete reflection is obtained if the wires are positioned horizontally.
- the reflected radar radiation will now impinge on a flat mirror 9 that is provided with polarization-twisting reflection means, for instance metal wires that are angled 45 degrees with respect to the polarization direction of the radar radiation in combination with a reflecting mirror, located at a distance of a quarter of the wavelength of the radar radiation. As is generally known in radar technology, this will reflect the polarization direction, however, with a polarization direction that has been twisted 90 degrees with respect to the original polarization direction. As a result, the radar radiation will, after the second impingement upon the parabolic reflector 8, leave the Cassegrain antenna 1.
- polarization-twisting reflection means for instance metal wires that are angled 45 degrees with respect to the polarization direction of the radar radiation in combination with a reflecting mirror, located at a distance of a quarter of the wavelength of the radar radiation.
- this will reflect the polarization direction, however, with a polarization direction that has been twisted 90 degrees with respect to the original polarization direction.
- Radar radiation reflected by a target is similarly supplie to feedhorn 7 in an identical way, entirely in agreement with the reciprocity principle for electro-magnetic radiation.
- the radar apparatus is furthermore provided with a radar transmission device 10 connected to the monopulse feedhorn and a radar reception device 11, which can both be integrated in the Cassegrain antenna 1. If Cassegrain antenna 1 is aimed at a target, radar reception device 11 produces, as is usual for a monopulse or a conical scan radar, an error voltage in elevation ⁇ B, an error voltage in azimuth ⁇ E, a sum voltage ⁇ and a distance R from the target to the radar for further processing.
- the radar apparatus as known in the art, is capable of providing information concerning the velocity V of the target.
- Fig. 3 represents a diagram of a first embodiment of the radar apparatus in operation with the gun.
- the error voltages ⁇ B, ⁇ E, ⁇ generated by the radar reception device, the target range R and the target velocity V are fed to radar dataprocessor and servo control device 12 which, in way well-known in the art, controls servo motor 5 and serv motor 6 such as to yield minimal error voltages. Barrel 3 will then be aimed directly at the target.
- a gun directly aimed at a target will generally miss this target, owing to the force of gravity affecting a round in flight and the target having its own velocity.
- it is usual to aim a gun with a certain lead angle t compensate for these and any other ballistic effects.
- this is possible by slightly rotating flat mirror 9.
- flat mirror 9 has been mounted movably, for instance by positioning it on top of actuators 13, as indicated in Fig. 2.
- actuators 13 By suitably driving actuators 13, a rotation of flat mirror 9 about its centre can be effected in any given direction through, for instance, an angle . This results in a rotation of the line of sight of the radar apparatus through an angle 2 ⁇ .
- a target as described above will be tracked in a first operational mode. From the data thus obtained, radar data processor and servo control device 12 will determine a desired lead angle. Prior to and during firing, the desired lead angle is realised in a second operational mode by a suitable control of actuators 13.
- gun 2 is provided with an azimuth encoder 14 and an elevation encoder 15, the values of which are fed to data processor and servo control device 12. Said encoders can also be advantageously used for initially aiming barrel 3 at a target, as the initial position of the target usually originates from another sensor. Dataprocessor and servo control device 12 will steer control servo motors 5 and 6 such that the position of barrel 3 corresponds with the received initial position, after which a search scan, well- known in the art will be executed.
- Actuators 13 may be designed as linear actuators based on the voice coil principle, the required rigidity and accuracy being obtained by means of a feedback loop. Furthermore it is of importance to select the radar transmit frequency of the radar apparatus to be high, as a result of which the dimensions of Cassegrain antenna 1 will be small and flat mirror 9 will as a consequence be small and light, so that a large bandwidth will be more easily attained.
- a suitable compromise between the dimensions of the Cassegrain antenna 1 on the one hand and the above- mentioned problems on the other hand is obtained at a radar transmit frequency of 15-30 GHz. At these radar transmit frequencies, it is required to compensate for said translations. Compensation is possible by means of flat mirror 9, by translating flat mirror 9 over a distance -d/2 at a translation of Cassegrain antenna 1 over a distance d.
- Fig. 4 represents a diagram of a second embodiment of the radar apparatus in operation with the gun, the above compensations having been realised.
- Cassegrain antenna 1 is provided with a sensor box 16, which generates the signals ⁇ and ⁇ representing the rotations in azimuth and in elevation.
- sensor box 16 generates a signal r representing the line of sight translation.
- sensor box 16 comprises a gravity-compensated acceleration sensor for accelerations in the direction of the line of sight, followed by an integrator.
- sensor box 16 for instance comprises a rate gyro for determining the angular velocities in azimuth and elevation followed by two integrators.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Variable-Direction Aerials And Aerial Arrays (AREA)
- Radar Systems Or Details Thereof (AREA)
- Aerials With Secondary Devices (AREA)
Abstract
Description
Claims
Priority Applications (11)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
UA95073426A UA26037C2 (en) | 1993-01-21 | 1994-01-12 | RADAR INSTALLATION |
DE69411151T DE69411151T2 (en) | 1993-01-21 | 1994-01-12 | RADAR DEVICE |
JP06516628A JP3035351B2 (en) | 1993-01-21 | 1994-01-12 | Radar equipment |
KR1019950703030A KR100282105B1 (en) | 1993-01-21 | 1994-01-12 | Radar device |
US08/481,387 US5574461A (en) | 1993-01-21 | 1994-01-12 | Radar apparatus for connecting to a gun |
PL94309780A PL172673B1 (en) | 1993-01-21 | 1994-01-12 | Radar apparatus |
BR9405813A BR9405813A (en) | 1993-01-21 | 1994-01-12 | Radar apparatus |
RU9495113732A RU2090825C1 (en) | 1993-01-21 | 1994-01-12 | Radar set |
CA002154185A CA2154185C (en) | 1993-01-21 | 1994-01-12 | Radar apparatus |
EP94905059A EP0680664B1 (en) | 1993-01-21 | 1994-01-12 | Radar apparatus |
GR980401784T GR3027606T3 (en) | 1993-01-21 | 1998-08-07 | Radar apparatus. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL9300113 | 1993-01-21 | ||
NL9300113A NL9300113A (en) | 1993-01-21 | 1993-01-21 | Radar device. |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1994017566A1 true WO1994017566A1 (en) | 1994-08-04 |
Family
ID=19861948
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP1994/000093 WO1994017566A1 (en) | 1993-01-21 | 1994-01-12 | Radar apparatus |
Country Status (16)
Country | Link |
---|---|
US (1) | US5574461A (en) |
EP (1) | EP0680664B1 (en) |
JP (1) | JP3035351B2 (en) |
KR (1) | KR100282105B1 (en) |
CN (1) | CN1054435C (en) |
BR (1) | BR9405813A (en) |
CA (1) | CA2154185C (en) |
CZ (1) | CZ285078B6 (en) |
DE (1) | DE69411151T2 (en) |
ES (1) | ES2119163T3 (en) |
GR (1) | GR3027606T3 (en) |
NL (1) | NL9300113A (en) |
PL (1) | PL172673B1 (en) |
TR (1) | TR27511A (en) |
UA (1) | UA26037C2 (en) |
WO (1) | WO1994017566A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1998014798A1 (en) * | 1996-10-02 | 1998-04-09 | Bauer Will N | System for 3d tracking of a remote point |
EP1819012A2 (en) * | 2006-02-10 | 2007-08-15 | Thales Holdings UK Plc | Antenna signal processing apparatus |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004144528A (en) * | 2002-10-23 | 2004-05-20 | Hitachi Ltd | Underwater sonar system |
CN101029928B (en) * | 2006-02-27 | 2011-02-09 | 中国科学院空间科学与应用研究中心 | Satellite scanning radar scatterometer for receiving and transmitting double wavebeam |
US7633431B1 (en) * | 2006-05-18 | 2009-12-15 | Rockwell Collins, Inc. | Alignment correction engine |
US8502744B2 (en) * | 2008-09-16 | 2013-08-06 | Honeywell International Inc. | Scanning antenna |
US10622698B2 (en) | 2013-08-02 | 2020-04-14 | Windmill International, Inc. | Antenna positioning system with automated skewed positioning |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2432261A5 (en) * | 1971-10-25 | 1980-02-22 | Arnaud Alain | DEVICE FOR STABILIZING THE SIGHT AND POINTING OF A MOBILE MEMBER |
US4450451A (en) * | 1982-03-03 | 1984-05-22 | Raytheon Company | Gimbal assembly for monopulse radar antenna |
EP0111192A1 (en) * | 1982-12-06 | 1984-06-20 | Hollandse Signaalapparaten B.V. | Integrated weapon control system |
EP0198964A1 (en) * | 1985-01-25 | 1986-10-29 | Bofors Electronics AB | An arrangement for fire control |
EP0352037A2 (en) * | 1988-07-20 | 1990-01-24 | The Marconi Company Limited | Weapon systems |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3683387A (en) * | 1970-12-28 | 1972-08-08 | Us Army | Compact scanning radar antenna |
US3924235A (en) * | 1972-07-31 | 1975-12-02 | Westinghouse Electric Corp | Digital antenna positioning system and method |
FR2406831A1 (en) * | 1977-10-21 | 1979-05-18 | Thomson Csf | MOBILE TARGET TRACKING SYSTEM |
USH205H (en) * | 1984-02-09 | 1987-02-03 | Wide bandwidth radar having improved signal to clutter response characteristics | |
US4901084A (en) * | 1988-04-19 | 1990-02-13 | Millitech Corporation | Object detection and location system |
US5075680A (en) * | 1990-09-14 | 1991-12-24 | Dabbs John W T | Method and apparatus for monitoring vehicular traffic |
US5281815A (en) * | 1992-03-03 | 1994-01-25 | Aai Corporation | Method of determining the humidity and temperature of atmospheric air |
-
1993
- 1993-01-21 NL NL9300113A patent/NL9300113A/en not_active Application Discontinuation
-
1994
- 1994-01-10 TR TR00032/94A patent/TR27511A/en unknown
- 1994-01-12 WO PCT/EP1994/000093 patent/WO1994017566A1/en active IP Right Grant
- 1994-01-12 DE DE69411151T patent/DE69411151T2/en not_active Expired - Fee Related
- 1994-01-12 EP EP94905059A patent/EP0680664B1/en not_active Expired - Lifetime
- 1994-01-12 ES ES94905059T patent/ES2119163T3/en not_active Expired - Lifetime
- 1994-01-12 PL PL94309780A patent/PL172673B1/en not_active IP Right Cessation
- 1994-01-12 KR KR1019950703030A patent/KR100282105B1/en not_active IP Right Cessation
- 1994-01-12 BR BR9405813A patent/BR9405813A/en not_active IP Right Cessation
- 1994-01-12 JP JP06516628A patent/JP3035351B2/en not_active Expired - Fee Related
- 1994-01-12 UA UA95073426A patent/UA26037C2/en unknown
- 1994-01-12 CZ CZ951890A patent/CZ285078B6/en unknown
- 1994-01-12 US US08/481,387 patent/US5574461A/en not_active Expired - Fee Related
- 1994-01-12 CA CA002154185A patent/CA2154185C/en not_active Expired - Fee Related
- 1994-01-18 CN CN94101104A patent/CN1054435C/en not_active Expired - Fee Related
-
1998
- 1998-08-07 GR GR980401784T patent/GR3027606T3/en unknown
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2432261A5 (en) * | 1971-10-25 | 1980-02-22 | Arnaud Alain | DEVICE FOR STABILIZING THE SIGHT AND POINTING OF A MOBILE MEMBER |
US4450451A (en) * | 1982-03-03 | 1984-05-22 | Raytheon Company | Gimbal assembly for monopulse radar antenna |
EP0111192A1 (en) * | 1982-12-06 | 1984-06-20 | Hollandse Signaalapparaten B.V. | Integrated weapon control system |
EP0198964A1 (en) * | 1985-01-25 | 1986-10-29 | Bofors Electronics AB | An arrangement for fire control |
EP0352037A2 (en) * | 1988-07-20 | 1990-01-24 | The Marconi Company Limited | Weapon systems |
Non-Patent Citations (1)
Title |
---|
CROSS ET AL.: "Mirror-Antenna Radar Concept", MICROWAVE JOURNAL., vol. 29, no. 5, May 1986 (1986-05-01), DEDHAM US, pages 323 - 335 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1998014798A1 (en) * | 1996-10-02 | 1998-04-09 | Bauer Will N | System for 3d tracking of a remote point |
EP1819012A2 (en) * | 2006-02-10 | 2007-08-15 | Thales Holdings UK Plc | Antenna signal processing apparatus |
EP1819012A3 (en) * | 2006-02-10 | 2008-05-07 | Thales Holdings UK Plc | Antenna signal processing apparatus |
Also Published As
Publication number | Publication date |
---|---|
PL172673B1 (en) | 1997-11-28 |
KR960700538A (en) | 1996-01-20 |
GR3027606T3 (en) | 1998-11-30 |
CN1093812A (en) | 1994-10-19 |
CZ285078B6 (en) | 1999-05-12 |
US5574461A (en) | 1996-11-12 |
EP0680664B1 (en) | 1998-06-17 |
DE69411151T2 (en) | 1999-01-14 |
TR27511A (en) | 1995-06-07 |
JP3035351B2 (en) | 2000-04-24 |
BR9405813A (en) | 1995-12-05 |
PL309780A1 (en) | 1995-11-13 |
CN1054435C (en) | 2000-07-12 |
EP0680664A1 (en) | 1995-11-08 |
CA2154185C (en) | 2001-07-24 |
JPH08505943A (en) | 1996-06-25 |
NL9300113A (en) | 1994-08-16 |
KR100282105B1 (en) | 2001-02-15 |
ES2119163T3 (en) | 1998-10-01 |
CA2154185A1 (en) | 1994-08-04 |
CZ189095A3 (en) | 1995-12-13 |
DE69411151D1 (en) | 1998-07-23 |
UA26037C2 (en) | 1999-02-26 |
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